1. Field of the Invention
The present invention relates to an apparatus and method for slitting boxes and more particularly, for cutting boxes containing rectangular objects without marring the box contents. The apparatus is particularly useful for cutting open boxes containing books and the like, without damaging the box contents.
2. Description of the Prior Art
It is long been desired in the art to be able to safely cut open boxes which package rectangular materials without damaging the contents. In the book publishing industry, sample books are often sent to consumers subject to their personal satisfaction and approval. As a consequence, such books are very often returned and must be processed by the publisher. Processing includes opening packaging materials and examining the returned items for damage. Books which are in excellent condition are available for resale, however, damaged books must be destroyed at great economic loss. Current practice in the art is for book return packages to be opened manually. Such labor intensive processing is very costly and one of the causes of book damage is human error in the opening process. The prior art has attempted to alleviate this problem by providing automated cutting equipment to open the returned packages. This has led to still further problems. Current box cutting machinery have blades which attack the box either perpendicularly or at an oblique angle to the plane of the book contents. In this regard, U.S. Pat. No. 5,048,267 teaches one cutting method for opening a rectangular package by forming a space between the package and the contents, cutting an edge, inserting a backplate and cutting the packaging on the surface of the backplate. This requires excessive manipulation steps. U.S. Pat. No. 5,074,097 shows a means for removing box tops by means of a cutting fluid under pressure. Such would not be useful for contents which must be kept dry. U.S. Pat. No. 5,275,524 shows an apparatus for cutting packaging material for cans by deforming the packing under vacuum conditions prior to cutting. This apparatus would not be useful for rectangular packaged items. U.S. Pat. No. 5,101,703 shows a box cutting method and apparatus using rotary knives disposed at an angle of approximately 45.degree. to the box side walls. Such would not accommodate boxes of varying sizes. U.S. Pat. No. 4,840,001 discloses a device for cutting only the tape supporting a box without cutting the box ends itself. This device would be inappropriate for boxes which are sealed with glue. U.S. Pat. No. 5,201,788 pertains to a device for cutting off the upper portion of a bottle and does not suggest usefulness for cutting boxes.
Since book packages are not of uniform size, the package presented to cutting machinery is often slashed too deeply thus irreparably damaging the contents. It has been found that by providing a box cutting apparatus with a blade which attacks the box parallel to and spaced from the plane of the book contents, that cutting damage is greatly reduced. If a blade penetrates the box at a depth greater than actually desired, the blade merely passes along side the book and does not damage it.
Typically boxes which are to be opened are constructed of corrugated paperboard. It has been found that during the shipping process, the corrugated materials often becomes warped. While the major panels of the corrugated materials were originally parallel and perpendicular to the planes of the book contents, the handling process often causes bending, twisting and or other distortions such that they are no longer perfectly square with the book planes. Thus, when a blade confronts the box parallel to the largest panel plane, there is still a risk of the box being improperly cut. However, corrugated boxes are extraordinarily strong and resistant to warping at its edges, corners and folds. The invention therefore provides an apparatus and method of cutting boxes parallel to and spaced from the plane of book contents and wherein the cut is made along a folded edge of the box from one corner to an adjacent corner of the box. It has now been unexpectedly found that when a box is cut in such a fashion, that boxes are reliably opened without damaging the contents.